Warp let-off motion

ABSTRACT

A warp let-off motion for a weaving machine, having a warp tension sensor responsive to changes in warp tension by varying its position, and a warp beam driven from a machine drive via an eccentric motion, a one-way clutch and a self-locking transmission. The let-off motion includes a pivotally mounted body driven from the weaving machine drive, in said body, there being swingingly mounted on angular lever, one end of the angular lever being connected to the warp, tension sensor, and the other end being swingingly connected to a slide means mounted on said body for sliding perpendicularly to the axis of pivotal mounting of the body. The slide means is connected by a connecting rod with a swinging arm of the one-way clutch.

United States Patent Pech et al. 1 5] Nov. 25, 1975 [54] WARP LET-OFFMOTION 2.920.659 1/1960 Pfarrwaller 139/110 .r. 2.946.352 7/1960 M K .1139/110 [75] mentors: g f f y g Km; Zbynek 3.122.172 2/1964 111111623 2:139/110 espesny, a 0 mo, Czechoslovakia Primarv Emminer James Kee Chi[73] Assignee: Vyzkumny ustav bavlnarsky, Usti I nad Orlici.Czechoslovakia ABSTRACT 99 [-7] Filed June 1973 A warp let-off motionfor a weaving'machine, having a [21] Appl. No.: 366,659 warp tensionsensor responsive to changes in warp tension by varying its position,and a warp beam driven from a machine drive via an eccentric motion,[30] Forelgn Apphcatlon pnmy Data a one-way clutch and a self-lockingtransmission. The June 2. 1972 Czechoslovakia 3813-72 let off motionincludes a pivotal), mounted body 7 driven from the weaving machinedrive, in said body, [5.] US. Cl .7 139/110 there being swinginglymounted on angular lever, one [51] Illl. Cl. D031) 49/06 end f theangular lever i g connected to the warp [58] Field of Search 139/110,109, 104, 103, tension Sensor, and the other end being swingingly.139/100 97; 66/86 A; connected to a slide means mounted on said body forsliding perpendicularly to the axis of pivotal mounting 156] Referencesof the body. The slide means is connected by a con- UNITED STATESPATENTS necting rod with a swinging arm of the one-way 2.635.646 4/1953Payne 139/110 u 2.819.734 1/1958 Pfarrwaller 1 139/110 2.878.839 3/1959Clentimack 139/110 7 Clam, 5 Drawing Flgures US. Patent Nov. 25, 1975Sheet10f4 3,921,676

U.S. Patent Nov. 25, 1975 Sheet 2 of 4 U.S. Patent Nov. 25, 1975Sheet3of4 3,921,676

US. Patent Nov. 25, 1975 Sheet4 Of4 3,921,676

FIG. 5

This invention relates to a motion for letting off warp from a warpbeam, said motion being controlled by the warp tension of the weavingmachine.

A motion for letting off warp from the warp beam is known wherein thetorsional moment for driving the warp beam is transmitted to aneccentric means with pivotally mounted pull rod. To this pull rod thereare swingingly connected two pull rods: a control rod and a main rod.The control rod, which permits the rod of the eccentric means to swing,is adjustably disposed. The main rod connects the rod of the eccentricmeans with a one-way clutch which transfers the main rod movement with agradual rotary movement whereby to drive the warp beam. The position ofthe swing direction of the eccentric .rod varies according to theadjusted position of the control rod, andaccordingly the swing length,by means of which the main rod acts on the one-way clutch, alsovaries.The'position of the control rod is controlled by varying the position ofa warp tension sensor. The disadvantages of this motion consistparticularly in a considerably complicated structure, and a lowsensitivity to the variation in warp tension because the variation inposition of the control rod requires a relatively great force andconsequently a relatively great energy from the warp tension sensor.

The motion, according to the present invention, has as an object theelimination of the above mentioned disadvantages. In accordance with theinvention, there is provided a pivotally mounted body, driven from theweaving machine drive, in the interior of which an angular lever isswingingly mounted, one end of the angular lever being connected to thewarp tension sensor and the other end of the angular leverbeingswingingly connected to a slide means mounted slidably in adirection perpendicular to the axis of pivotal mounting of the body. Theslide, means is connected e.g., by .means of a connecting rod with aswinging arm of a one-way clutch connected by a transmission with thewarp beam of the weaving machine. I

The principal advantages of the motion, according to the invention, area great sensitivity to thewarp tension variation in the course ofweaving, and the fact that for varying the letting off velocity onlylittle force or energy from the warp tensionsensor suffices. Furtheradvantages of the motion are a relative simplicity, good servicereliability, and long useful life.

An illustrative embodiment of the motion, according to the invention, isshown in the accompanying drawings, in which:

FIG. 1 is front view of the motion of the invention for letting off warpfrom a warp beam of a weaving machine;

FIG. 2 is a side view of the let-off motion shown in FIG. I;

FIG. 3 is a side view, partially insection, of the let-off motion; 1 I

FIG. 4 is a detail view of an one-way clutch of the letoff motion, and

FIG. 5 is an enlarged detailed view of mechanism which is somewhatschematically shown at the lower left of FIG. 3 of the drawing, certainof the parts being shown in section and others of the parts being shownin elevation.

On the frame 1 of a weaving machine there is pivotally mounted a warpbeam 2. The warp 3, wound on the warp beam 2, is conducted via aback-rest roller 4 to two-similar paralleltension levers 5 which tensionthe warp 3. The tensioning forceof springs 6 is adjusted by set screws7. The back-rest roller 4 on the levers 5 biased by springs 6 alsofunctions as a warp tension sensor reacting by varying itsposition tovariations in tension of the warp 3.

The let-off motion of the loom or weaving machine is used for drivingthe warp beam 2. Such let-off motion is formed by body 9 pivotallymounted in the housing 10 upon the frame 1 of the machine. An angularlever 11 is swingingly mounted in the interior of the body 9 on a pivotpin 12, one end of said leverll closely cooperating with the warptension sensor. In the illustrative embodiment such one end of theangular lever 11 is swingingly connected to a pull rod 13. Rod 13 isswingingly and non-rotatably connected e.g., by a pin 14 with a bushing15 mounted slidably in. an axial direction in spring 16 into contactwith the arm 8 of the tension lever 5 e.g., via a swingingly mountedpush button-l7.

The other end of the angular lever 11 is swingingly connected to a slidemeans 18 which is mounted for sliding in a direction perpendicular tothe axis 20 of pivotal mounting of the body 9 in the guide 19. The slidemeans 18 can change its eccentricity in the guide 19 from maximum at theend of the guide 19 of the body 9 to zero at the beginning of the guide19 in the axis 20 of the body 9, as shown in FIGS. 3 and 4.

The body 9 of the motion is further connected e.g., via a bevel gear set21, 22, to the gear 22 being affixed to a shaft 22, which is connectedto the drive of the weaving machine (not shown).

A connecting rod 23 is pivotally connected to the slide means 18 fortransmitting the rotational movement from the machine drive to the warpbeam 2. The connecting rod 23 is swingingly connected to an arm 25 of aone-way clutch 24. Clutch 24 is connected with the warp beam 2 via aworm 38 on the shaft 26 of the clutch 24 and a worm wheel 39 on theshaft 40 of the warp beam 2.

It is advantageous to use as one-way clutch 24 a oneway clutch withrolling contact elements. In the illustrative embodiment shown in FIG.4, the clutch has a sleeve or drum 27 on which there is arranged an arm25 for connection with the connecting rod 23, the drum 27 beingpivotally mounted on the hub 28 of the clutch. In the hub 28 there areformed wedge seats 29 for the rolling-contact elements 30, which may bespring loaded rollers, as shown. To the shaft 26 of the clutch 24, thereis secured a ring or disc 31, disc 31 being provided with lugs 32 whichcan rotate in the hub 28 of the clutch 24. Pull rods 33 are slidablymounted in the hub 28 between stops 35 and 36 which are disposedtangentially to the ring 31, pull rods 33 having the recesses 34 whichreceive lugs 32 on the ring 31. In the position shown in FIG. 4, inwhich the pull rods engage the first stops 35, the pull rods 33 preventthe rolling-contact elements 30 from driving engagement with theirseats. In the second position in which the rods .33 engage the secondstops 36, the elements 30 transmit the rotation of the hub 28 of theclutch 24 in one direction to the shaft 26 of the clutch 24 via the disc31, the one-way clutch 24, thus functioning in its normal manner.

On the prolongation of the shaft 26 of the clutch 24 there is mounted ahandwheel 37 for the manual rotation of the warp beam 2. The one-wayclutch 24 permits such normal rotation of the warp beam in the directionof its normal function. During the angular rotation of the warp beam inthe direction opposite to the normal function, the pull rods 33 in thehub 28 of the clutch 24 disable the one-way clutch 24.

FIG. 5, which is in an enlarged constructional view of the mechanismshown schematically at the lower left of FIG. 3, shows the shaft 22 uponwhich bevel 22 is mounted, the cavity in the slide means 18 and therounded end 44 of the angle level 11 which is receded in said cavity. Itwill be understood that FIG. 4 is a view of the front end 45 of the body9, and that in FIG. 5 only the part 46 of the slide means 18intended forthe pivotal mounting of the connecting rod 23 is shown in section.

In the course of weaving, the required tension of the warp 3 is adjustedby adjusting the tension of springs 6 by set screws 7. Further,adjustment of warp tension, if necessary, is effected by use of thehandwheel 37. When the tension does not vary, i.e., the rate of lettingoff of the warp 3 from the warp beam 2 is equal to the rate ofwithdrawal of the warp 3, the eccentric position of the slide means 18does not vary and corresponds to the length of the warp 3 withdrawnduring one revolution of the machine. The rotational movement of theslide means 18, caused by rotating the body 9 by the weaving machinedrive, is transformed by the connecting rod 23 in a swinging movement ofthe arm 25 of the one-way clutch 24. The angular displacement of the hub28 of the clutch 24' is transmitted via the shaft 26 of the clutch, worm38 and worm wheel 39 to the shaft 40 of the warp beam 2. If the tensionof the warp 3 rises, i.e., the rate of letting off warp 3 issmaller thanthe rate of warp 3 withdrawn, the position of the tension lever 5changes and its arm 8, by varying the position of the push button 17,increases the eccentricity of the slide means 18 which results inincreasing the rate of letting off warp 3 and the tension of the warp isrestored to the desired value.

The warp let-off motion of the invention is especially applicable in thecontinuous withdrawal of warp, e.g., in a wave-type weaving machinewhere the back-seat roller does not substantially vary its positionduring normal operation. In weaving machines with a greater change inwarp tension it is preferred to incorporate a yieldable means such as aspring between the push button 17 and the arm 8 of the tension lever -5,for example, so that only the intermediate position of the tension lever5 causes a variation in the eccentric position of the slide means 18.

Although the invention is illustrated and described with reference to aplurality of preferred embodiments thereof, it is to be expresslyunderstood that it is in no way limited to the disclosure of such aplurality of preferred embodiments, but is capable of numerousmodifications within the scope of the appended claims.

What is claimed is:

1. In a weaving machine, having a machine drive, a

off motion including means for driving the warp beam.

from the machine drive via an eccentric motion, oneway clutch and aself-locking transmission, the improved warp let-off motion whichcomprises a pivotally mounted body driven from the weaving machinedrive, a connecting means movably mounted in said body, one end of themovable connecting means being connected to the warp tension sensor, aslide means mounted in the body for sliding perpendicularly to the axisof pivotal mounting of the body, the other end of the connecting meansbeing pivotally connected to the slide means; the one-way clutch havinga swinging arm and a connecting rod, connecting the slide means with theswinging arm of the one-way clutch.

2. The let-off motion of claim 1, wherein the connecting means is alever, and comprising pivot means housing mounted axially within thebody for rotation therewith and axial reciprocation with respectthereto,

a pull rod pivotally attached to said one end of the lever, meanspivotally attaching the pull rod to the housing, a spring opposingaxially inward movement of the housing with respect to the body, andmeans connecting the warp tension sensor to the pull rod in oppositionto the spring. a

5. A let-off motion, according to claim 1, wherein the one-way couplingis mounted on a clutch shaft, a disc with spaced lugs attached to theclutch shaft, the clutch having a hub which is pivotally mounted on theclutch shaft, and pull rods mounted in the hub of the clutch tangent andconnected to the disc to said lugs so as to be reciprocatedthereby, saidpull rods selectively dis abling the clutch from its normal one-wayaction.

6. A let-off motion, according to claim 5, wherein the clutch haswedge-shaped seats, each having an apex in the hub, a drum coaxial ofthe clutch shaft, surrounding the hub, and a rolling clutch element ineach seat the radially outer ends of the pull rods extending into therespective seats and selectively restraining the rolling. I

elements from movements toward the apex of the respective seat.

7. A let-off motion, according to claim 6, comprising first and secondstops disposed longitudinally of the respective pull rods to define thelimits of movement of the pull rods between a first position in whichthe pull rods restrict the rolling elements from movement toward theapex of the respective seat and a second position in which the pull rodsare retracted to permit movement of the rolling elements toward saidapices of the seats.

1. In a weaving machine, having a machine drive, a warp tension sensorresponsive to the changes in warp tension by varying its position, awarp and a warp let-off motion including means for driving the warp beamfrom the machine drive via an eccentric motion, one-way clutch and aself-locking transmission, the improved warp let-off motion whichcomprises a pivotally mounted body driven from the weaving machinedrive, a connecting means movably mounted in said body, one end of themovable connecting means being connected to the warp tension sensor, aslide means mounted in the body for sliding perpendicularly to the axisof pivotal mounting of the body, the other end of the connecting meansbeing pivotally connected to the slide means; the one-wAy clutch havinga swinging arm and a connecting rod, connecting the slide means with theswinging arm of the one-way clutch.
 2. The let-off motion of claim 1,wherein the connecting means is a lever, and comprising pivot meansmounting the lever in said body.
 3. The let-off motion of claim 2,wherein the lever is an angular lever having two angularly disposedarms, and the pivot means is disposed at the junction of such two armsof the angular lever.
 4. The let-off motion of claim 2, wherein theconnection of said one end of the connecting means to the warp tensionsensor is effected by means including a housing mounted axially withinthe body for rotation therewith and axial reciprocation with respectthereto, a pull rod pivotally attached to said one end of the lever,means pivotally attaching the pull rod to the housing, a spring opposingaxially inward movement of the housing with respect to the body, andmeans connecting the warp tension sensor to the pull rod in oppositionto the spring.
 5. A let-off motion, according to claim 1, wherein theone-way coupling is mounted on a clutch shaft, a disc with spaced lugsattached to the clutch shaft, the clutch having a hub which is pivotallymounted on the clutch shaft, and pull rods mounted in the hub of theclutch tangent and connected to the disc to said lugs so as to bereciprocated thereby, said pull rods selectively disabling the clutchfrom its normal one-way action.
 6. A let-off motion, according to claim5, wherein the clutch has wedge-shaped seats, each having an apex in thehub, a drum coaxial of the clutch shaft, surrounding the hub, and arolling clutch element in each seat the radially outer ends of the pullrods extending into the respective seats and selectively restraining therolling elements from movements toward the apex of the respective seat.7. A let-off motion, according to claim 6, comprising first and secondstops disposed longitudinally of the respective pull rods to define thelimits of movement of the pull rods between a first position in whichthe pull rods restrict the rolling elements from movement toward theapex of the respective seat and a second position in which the pull rodsare retracted to permit movement of the rolling elements toward saidapices of the seats.